Torque limiting clutch

ABSTRACT

There is disclosed a torque limiting clutch having a pair of cooperable torque transmitting members coupled by a pair of clutch members. Torque is transmitted via leaf spring means secured to one torque transmitting member and one clutch member. The leaf spring means is bowed and urges the clutch members together. The amount of torque which the clutch can transmit before slippage occurs between the clutch members is adjustable by changing the amount of bowing in the leaf spring means.

United States Patent Chinlund, deceased et al.

[ 51 May 16, 1972 [54] TORQUE LIMITING CLUTCH [72] Inventors: Joseph F.Chinlund, deceased, 1224 Glenoak Lane, late of Northbrook, Ill. 60062,Carol B. Chinlund, executrix 22 Filed: Mar. 19, 1970 [21] Appl.No.:20,956

[52] US. Cl. t ..64/30 C, 192/89 B [51] Int. Cl ..Fl6d 7/02 [58] Fieldof Search ..64/30 R, 30 C; 192/56, 89 B [56] References Cited UNITEDSTATES PATENTS 2,503,262 4/1950 Hall ..64/30 C UX 2,050,542 8/1936 Pace..64/30 C UX 923,134 6/1909 Brown ..64/30 R X 3/1953 Holstein ..64/30 Rx Ragan ....64/30 C UX Primary Examiner-Allan D. HerrmannAttorney--Mason Kolehmainen and Rathbum & Wyss This application filedunder Rule 47.

[57] ABSTRACT There is disclosed a torque limiting clutch having a pairof cooperable torque transmitting members coupled by a pair of clutchmembers. Torque is transmitted via leaf spring means secured to onetorque transmitting member and one clutch member. The leaf spring meansis bowed and urges the clutch members together. The amount of torquewhich the clutch can transmit before slippage occurs between the clutchmembers is adjustable by changing the amount of bowing in the leafspring means.

9 Claims, 4 Drawing Figures TORQUE LIMITING CLUTCH This inventionrelates to the art of torque limiting clutches.

The invention comprises an improved arrangement of components includinginput and output torque transmitting members coupled by bowed leafspring means which transmits torque and which enables the force betweencooperating clutch members to be adjusted by varying the amount ofbowing of the leaf spring means. i

In accordance with a specific embodiment of the invention there areprovided a pair of collars secured to a shaft, a torque transmittingmember rotatably received by and with respect to the shaft, a frictionalclutch member secured to or formed on the torque transmitting member, amounting plate received by the shaft for mounting another frictionalclutch member, and

leaf spring means secured to one of the collars and to themountingplate. The leaf spring means exerts a force which urges the clutchmembers into clutching engagement with each other. Adjustment of theposition of one of the collars effects adjustment of the amount of forceexerted by the leaf spring means. It is preferred to use two leafsprings, each having two sections. The force exerted by the sections onthe clutch members is uniform. The sections are placed under stress andare normally bowed to such an extent that they press the clutch memberstogether with the desired amount of force.

In the drawings:

FIG. 1 is a view, mainly in section, of a torque limiting clutch inaccordance with the invention; and

FIGS. 2, 3 and 4 are sectional views taken along respective lines 22,3-3 and 44, of FIG. 1.

In the drawings, there is shown a torque limiting clutch generallyindicated at 10. A shaft 11 is shown to be rotatably mounted by abearing 12 mounted in a frame 13. Collars 14 and 15 are disposed on theshaft 11 at spaced apart locations. Set screws 16 adjustably secure thecollar 14 to the shaft 11, and a set screw 17 adjustably secures thecollar 15 to the shaft 11. Any other suitable means for adjustablysecuring the collars 14 and 15 to the shaft 11 can be provided. A torquetransferring member 18, specifically a spur gear, has a central bore 19through which the shaft 11 extends. The member 18 is freely rotatableabout and axially shiftable relative to the shaft 11. A bearing orpressure plate 20 has its one side surface in abutment with the collar15 and its other side surface in abutment with one side surface of themember 18. A mounting plate 21 has a bore 22 through which the shaft 1 1extends. The plate 21 is shiftable axially along the shaft 11.

A frictional member 23 shown to take the form of a clutch plate issuitably secured to one side of the member 18, and a frictional member24 shown to take the form of a clutch plate is secured to one side ofthe mounting plate 21.

Torque and axial force tending to press the frictional members 23 and 24together is illustrated as being exerted by leaf springs 25 and 26. Bothleaf springs 25 and 26 are normally flat, but in the assembled positionshown in the drawing they are stressed and bowed. Each leaf spring 25and 26 is secured to the collar 14 at its midsection by rivets 27. Thespring 25 is considered to have two bowed sections 28 and 29, and thespring 26 is considered to have two bowed sections and 31. Ends 28 and29' ofsections 28 and 29 and ends 30 and 31' of sections 30 and 31 aresecured to the mounting plate 21, at equally spaced apart locationsabout the shaft 11, by rivets 32. In the position shown in FIG. 1, allfour sections 28 through 31 are bowed through angles of about 180, andare disposed 90 apart.

Gear 18 is shown to be in meshing engagement with a spur gear 33adjustably secured to shaft 34 by a set screw 33. The shaft 34 isillustrated as being rotatably mounted by a bearing 35 mounted in theframe 13. The shaft 34 can either be a driving shaft or a driven shaft.More specifically, the clutch 10 will perform its intended functionirrespective of whether the gear 18 or the gear 33 is the driving gearor the driven gear.

In operation, let it be assumed that gear 33 is the driving gear andthat gear 18 is the driven gear, and that the maximum transmitted torguefor which the clutch 10 is adjusted is not being exceede The clutchmember 23 drives the clutch member 24 and its mounting member or plate21. The leaf springs 25 and 26 transmit torque to the collar 14 andhence to the shaft 11. In short, the member 18 and its frictional member23, the collars l4 and 15, the pressure plate 20, the mounting plate 21and its frictional member 24, the leaf springs 25 and 26 and the shaft11 rotate as a unit. If the torque for which the clutch 10 is adjustedis exceeded, slippage will occur between frictional members 23 and 24,and hence the torque attempted to be transmitted between shafts 34 and18 is limited.

In order to adjust the amount of torque which can be transmitted by theclutch 10, the set screws 16 can be loosened and the collar 14 can beshifted axially on the shaft 11 to the desired position, and the setscrews can be tightened. Accordingly, the clutch 10 will transmit eithermore or less torque depending on the direction in which the collar 14was shifted relative to the shaft 1 1. Alternatively, the clutch 10 canbe adjusted by loosening the set screw 17, shifting the collar axiallyto the desired position on the shaft 11, and thereupon tightening theset screw 17. If this alternative adjustment is used, one of the gears,such as the gear 33, can be made wider than the other gear 18 as shownin FIG. 1 so that there will always be full contact therebetween toobviate changing the adjusted position of the gear 33 with respect tothe shaft 34.

What is claimed is:

1. A torque limiting clutch, comprising: a shaft, first and secondcollars received by and secured to said shaft at spaced apart locations,means for adjustably securing at least one of said first and secondcollars to said shaft, a torque transmitting member received by saidshaft and rotatable relative to said shaft, a first clutch platereceived about said shaft and secured to said torque transmittingmember, a second clutch member received about said shaft and beingcooperable with said first clutch plate, a mounting plate secured tosaid second clutch member and received about said shaft, and leaf springmeans secured to said first collar and to said mounting plate.

2. A torque limiting clutch as defined in claim 1, wherein said leafspring means includes a leaf spring which is bowed, and said means foradjustably securing one of said collars enables the amount of bowing tobe adjusted.

3. A torque limiting clutch as defined in claim 1, wherein said leafspring means includes a leaf spring having a pair of ends and amidsection, said midsection being secured to said first collar and saidends being connected to said mounting plate.

4. A torque limiting clutch as defined in claim 1, wherein said leafspring means includes a plurality of leaf springs.

5. A torque limiting clutch as defined in claim 1, wherein said meansfor adjustably securing one of said collars enables said collar to beshifted along said shaft and to be held in its adjusted position.

6. A torque limiting clutch as defined in claim 1, wherein said meansfor adjustably securing one of said collars includes means foradjustably securing one of said collars to a desired positionlongitudinally along said shaft.

7. A torque limiting clutch as defined in claim 1, wherein said leafspring means includes a pair of bowed sections, each of said sectionsbeing bowed through about 8. A torque limiting clutch as defined inclaim 1, wherein said leaf spring means includes a pair of oppositelydisposed leaf spring sections.

9. A torque limiting clutch as defined in claim 1, including a pair ofleaf springs offset with respect to each other, each leaf spring beingsecured to said first collar and to said mounting plate.

1. A torque limiting clutch, comprising: a shaft, first and second collars received by and secured to said shaft at spaced apart locations, means for adjustably securing at least one of said first and second collars to said shaft, a torque transmitting member received by said shaft and rotatable relative to said shaft, a first clutch plate received about said shaft and secured to said torque transmitting member, a second clutch member received about said shaft and being cooperable with said first clutch plate, a mounting plate secured to said second clutch member and received about said shaft, and leaf spring means secured to said first collar and to said mounting plate.
 2. A torque limiting clutch as defined in claim 1, wherein said leaf spring means includes a leaf spring which is bowed, and said means for adjustably securing one of said collars enables the amount of bowing to be adjusted.
 3. A torque limiting clutch as defined in claim 1, wherein said leaf spring means includes a leaf spring having a pair of ends and a midsection, said midsection being secureD to said first collar and said ends being connected to said mounting plate.
 4. A torque limiting clutch as defined in claim 1, wherein said leaf spring means includes a plurality of leaf springs.
 5. A torque limiting clutch as defined in claim 1, wherein said means for adjustably securing one of said collars enables said collar to be shifted along said shaft and to be held in its adjusted position.
 6. A torque limiting clutch as defined in claim 1, wherein said means for adjustably securing one of said collars includes means for adjustably securing one of said collars to a desired position longitudinally along said shaft.
 7. A torque limiting clutch as defined in claim 1, wherein said leaf spring means includes a pair of bowed sections, each of said sections being bowed through about 180*.
 8. A torque limiting clutch as defined in claim 1, wherein said leaf spring means includes a pair of oppositely disposed leaf spring sections.
 9. A torque limiting clutch as defined in claim 1, including a pair of leaf springs offset with respect to each other, each leaf spring being secured to said first collar and to said mounting plate. 